It sounds like that has been done away with. From MLB
Claiming priority is based on reverse winning percentage. So, if a player is placed on outright waivers and claimed by more than one team, the team with the worse winning percentage gets priority.
A previous version of the rules gave priority based on the league of the team waiving the player, with NL teams getting priority for NL players, and AL for AL, but that is no longer the case.